--- a/xio-openssl.c
+++ b/xio-openssl.c
@@ -8,6 +8,8 @@
 #if WITH_OPENSSL	/* make this address configure dependend */
 #include <openssl/conf.h>
 #include <openssl/x509v3.h>
+#include <openssl/dh.h>
+#include <openssl/bn.h>
 
 #include "xioopen.h"
 
